On this day in 1804, ownership of the territory of Louisiana was transferred to the United States. The U.S. bought the land from Napoleon’s France and thus doubled its territory. The purchase agreement was signed the year before, in 1803. The purchased land had 2,140,000 square kilometers. The U.S. paid only $15 million for this territory, which amounts to only 7 cents per hectare. Today, this territory encompasses as many as 15 U.S. states.

It is interesting that Napoleon Bonaparte is largely credited for this expansion of the United States territory. Only a few years before, he acquired the land from Spain by pressing it to cede this territory. Although there was even some resistance to this purchase in the U.S., President Thomas Jefferson decided to take the fateful step and thus easily doubled the territory of his young state. That was very likely the largest land transaction in world history, because the sale involved a territory larger than many historical empires (for example, the Napoleon’s entire empire in Europe, together with its associated countries, was smaller than that land).